Striking McDonald’s workers in the union-backed “Fight For $15” movement are demanding that the company stop seeking advice on sexual harassment policy from a law firm that is currently defending the Weinstein Co.

Fight For $15, an initiative of the Service Employees International Union to raise pay and unionise the fast food industry, planned to mount a day-long strike on Tuesday against McDonald’s to raise awareness of alleged sexual harassment at some of its restaurants. They’re also demanding that McDonald’s dump the workplace training arm of Seyfarth Shaw, a Chicago-based law firm that defends companies against workplace claims.

The National Organisation for Women and the National Women’s Law Centre have alleged that workers at McDonald’s outlets “face rampant sexual harassment”. McDonald’s workers backed by such groups have filed more than a dozen sexual harassment complaints with the US Equal Employment Opportunity Commission over the past two years. Allegations in the filings include groping, inappropriate comments from supervisors, and retaliation for speaking up.

McDonald’s declined to immediately comment. In May, following the most recent EEOC complaints, a company spokeswoman said “There is no place for harassment and discrimination of any kind in our workplace. McDonald’s Corp. takes allegations of sexual harassment very seriously and are confident our independent franchisees ... will do the same.”

Last week, the fast-food chain announced it was hiring experts to help “evolve” its sexual harassment policy, including representatives from an anti-sexual violence group and Seyfarth Shaw’s training unit. Over the past decade, Seyfarth has represented companies facing sexual harassment claims including Nike Retail Services, Domino’s Pizza and United Continental Holdings. Seyfarth is currently defending the Weinstein Co. against a proposed racketeering class action lawsuit alleging the company was complicit in film producer Harvey Weinstein’s sexual misconduct.

Seyfarth, an 850-lawyer global law firm, did not provide comment in response to several inquiries. In May, Gerald Maatman, the Seyfarth partner representing Weinstein Co., said he prefers to have men on the jury in a sexual harassment case because some of them might be more sceptical. He also said he prefers older jurors because they can “have a more measured idea of how businesses work”.

Fight For $15 said such comments should disqualify Seyfarth from providing McDonald’s with advice on preventing sexual harassment. Maatman declined to comment when contacted on Monday.

Most companies primarily look to management-side law firms for guidance on developing their sexual harassment policies, said Jenny Yang, who chaired the EEOC under President Barack Obama and is now a fellow at the Open Societies Foundation and an adviser to a company that consults for companies and non-profits.

However, such law firms may end up focusing more on preventing litigation than preventing harassment, she said.